As the post points out, “The primary hardware issue is level conversion. The RPB is a 5V design and the CC3000 module operates at 3.3V. Communication between the modules happens via SPI. You must also use a linear regulator to power the CC3000 module from a voltage reference on the RPB.”

The WiFi module discussed herein is TI Part No. CC3000TIWISLEM and is available from their estore for $49.00.